Decorative coatings providing a multicolor, textured surface

Abstract

A multitone or multicolor decorative, textured coating on a substrate comprises rigid, spheroidal polymeric beads distributed in a random pattern and embedded in a coherent coating film comprising a film-forming polymer. The beads may be colored and are of a defined size relative to the coherent coating film thickness and there is a contrast in tone or color between the coherent coating film and at least some of the beads. The coating is obtained on a substrate by applying to the substrate with a roller applicator a coating composition which contains beads of defined size.

We claim: 
     
       1. A multitone or multicolour, decorative, textured coating on a substrate, the coating comprising 15-95% by volume, based on the total dry coating volume, of rigid, spheroidal, polymeric beads distributed in a random pattern and embedded in a coherent dry coating film which comprises a film-forming polymer, wherein: (a) the rigid polymeric beads have an effective maximum diameter (as herein defined) which is within the range 1.2 to 3.5 × (the overall average thickness of the coherent dry coating film - which is defined as the quotient of the total weight of the coherent coating film per unit area divided by the density of the total coherent coating film) but where up to 5% by weight of the individual beads, based on the total weight of the beads, may have a diameter greater than the effective maximum diameter;   (b) the overall size of the beads is such that 90% by weight of the beads have a diameter which is within the range 0.6 to 3.0 × (the overall average thickness of the coherent dry coating film):   (c) at least 40% by weight of the beads have a diameter which is within the range 0.5 to 1.0 × (the effective maximum diameter of the beads); and   (d) there is a contrast in tone or colour between the coherent dry coating film and at least some of the rigid polymeric beads.   
     
     
       2. A coating according to claim 1 which has a fine texture. 
     
     
       3. A coating according to claim 1, wherein the overall average coherent film thickness is in the range 30-45 microns and the effective maximum diameter of the beads is in the range 90-150 microns. 
     
     
       4. A coating according to claim 3, wherein at least 40% by weight of the beads have a diameter which is within the range 30-150 microns. 
     
     
       5. A coating composition suitable for application to a substrate by a roller applicator to produce a multitone or multicolour, decorative, textured coating, which comprises a dispersion of a film-forming polymer and rigid, spheroidal polymeric beads in a liquid medium wherein: (a) the rigid polymeric beads have an effective maximum diameter (as herein defined) which is within the range 1.2 to 3.5 × (the overall average thickness of the coherent dry coating film as herein defined) but where up to 5% by weight of the individual beads may have a diameter greater than the effective maximum diameter;   (b) the overall size of the beads is such that 90% by weight of the said beads have a diameter which is within the range 0.6 to 3.0 × (the overall average thickness of the coherent dry coating film);   (c) at least 40% by weight of the beads have a diameter which is within the range 0.5 to 1.0 × (the effective maximum diameter of the beads).   
     
     
       6. A coating composition according to claim 5, wherein the liquid medium is an aqueous medium. 
     
     
       7. A coating composition according to claim 6, wherein the film-forming polymer is a latex polymer. 
     
     
       8. A coating composition according to claim 5, wherein the pigment volume concentration is in the range 15-95%. 
     
     
       9. A coating composition according to claim 5, wherein at least some of the beads are coloured. 
     
     
       10. A coating composition according to claim 5, wherein the beads are prepared by suspension polymerisation. 
     
     
       11. A method of obtaining a decorative coating on a substrate, wherein a coating composition according to claim 5 is applied to the substrate from a roller applicator. 
     
     
       12. A coating composition according to claim 5 which comprises a pigment which will provide, in the dry coating to be produced, a contrast in tone or colour with at least some of the rigid polymeric beads.